The present invention relates to article transport equipment and, more particularly, equipment which conveys generally flat, flexible web products along a product path, removes the products from the path, and stacks the products.
Various article transport equipment has been devised in the past to convey, and stack flexible web products, such as for example plastic food bags. One such plastic bag of this type is shown in U.S. Pat. No. 4,358,466, issued Nov. 9, 1982, to Stevenson. The bag includes a zipper locking mechanism and, additionally, includes wing-shaped pouch portions.
In one type of bag fabricating equipment, two parallel streams of bags are produced, conveyed along a pair of generally parallel transport paths by a pair of vacuum belt conveyors, engaged by grippers carried on a rotary support, termed an inverter roll, and removed from the path. The articles are then deposited on a support surface by the inverter roll where they are stacked prior to being packaged.
From time to time, the bags produced by the fabricating equipment and supplied to the article transport equipment will not be suitable for packaging, but rather must be collected separately. This may occur, for example, at start-up of the fabricating equipment. At other times, only the bags in one transport path are defective and must be collected, while the bags in the other path are handled and packaged in the usual fashion.
It is desirable, therefore, to be able to cull bags from both transport paths or from only one path while permitting the bags transported in the adjacent parallel path to be packaged in a normal manner. Further, the bag transports typically include vacuum belt conveyor arrangements, and it is desirable that the removal of bags from one path be accomplished without altering the operation of the belt conveyor with respect to the other path.
It is seen, therefore, that there is a need for an arrangement for selectively removing articles from either or both of a pair of vacuum belt conveyors without altering the operation of the conveyors.